There's this idea that everything goes with Guile's theme. But sometimes, the Street Fighter character's music doesn't just make things better, but also makes them more adorable.
Perhaps you've seen this classic? It's even cuter with Guile's theme.
But, you know, there's some instances when you don't need to add Guile's theme. Take the above, unaltered video, for example. Forty seconds in, it already has it's own great theme music.